A finite strain model for fiber angle plasticity of textile fabrics based on isogeometric shell finite elements

TL;DR

This paper introduces a shear elastoplasticity model for textile fabrics that captures fiber angle rotation and inter-ply friction during large deformations, validated through experimental tests and integrated with isogeometric shell finite elements.

Contribution

It presents a novel elastoplasticity model based on fiber angle measures, directly formulated with surface invariants, and validated against experimental data.

Findings

Model accurately predicts shear behavior in textile fabrics.

Good agreement with experimental tests like the picture frame and bias extension.

Applicable to complex 3D shell problems.

Abstract

This work presents a shear elastoplasticity model for textile fabrics within the theoretical framework of anisotropic Kirchhoff-Love shells with bending of embedded fibers proposed by Duong et al. (2023). The plasticity model aims at capturing the rotational inter-ply frictional sliding between fiber families in textile composites undergoing large deformation. Such effects are usually dominant in dry textile fabrics such as woven and non-crimp fabrics. The model explicitly uses relative angles between fiber families as strain measures for the kinematics. The plasticity model is formulated directly with surface invariants without resorting to thickness integration. Motivated by experimental observations from the picture frame test, a yield function is proposed with isotropic hardening and a simple evolution equation. A classical return mapping algorithm is employed to solve the elastoplastic problem within the isogeometric finite shell element formulation of Duong et al. (2022). The verification of the implementation is facilitated by the analytical solution for the picture frame test. The proposed plasticity model is calibrated from the picture frame test and is then validated by the bias extension test, considering available experimental data for different samples from the literature. Good agreement between model prediction and experimental data is obtained. Finally, the applicability of the elastoplasticity model to 3D shell problems is demonstrated.